Farmers warned of potato blight outbreaks due to recent rainfall

Farmers are being warned that potato blight is likely to become very active in the coming weeks due to recent rainfall, according to Shay Phelan, a Potato Specialist for Teagasc.

Despite many growers keeping their spraying intervals tight, even during the dry weeks in July, Phelan said that blight pressure has kept building, with big canopies contributing to the problem.

He also said it was important to be extra vigilant on crops to reduce the risk of the disease spreading and becoming uncontrollable.

In your own crops, monitor areas in corners and around poles or anywhere less than full rates of spray are being applied as blight will spread from these areas.

“It may be necessary to apply fungicides in shorter intervals to try to dry up the fungus, otherwise where practical it may be necessary to burn off the affected areas if they become uncontrollable,” Phelan said.

To protect against tuber blight, contacts sprays such as Cyazofamid (Ranman) or Fluazanim (Shirlan/Volley) are probably the best option at this stage of the growing season, according to Phelan.

Meanwhile, Phelan added that reports from a number of growers indicate that tuber numbers will be low this year, with these tubers swelling fast and reaching a desirable size quickly.

“Depending on planting date growers should start inspecting crops in early August to assess the crops for burning off. It may well be a case that crops with lower tuber numbers may be fit to dessicate earlier than expected,” Phelan said.

The recent rainfall will also bring ideal conditions for slugs feeding on the soil surface therefore farmers need to take action and have barriers in place to protect the crop, according to Phelan.

“This is the only time in the year that the Keeled slug appears on the soil surface in order to mate. Make sure that a full rate of pellets is on the crop by the middle of August. Product choice shouldn’t make a huge difference but quantity probably will.

“As a general rule of thumb damage increases significantly once you move into September. Therefore, identify these fields and plan to harvest as soon as possible.”